Does Eemaan increase and decrease depending upon one’s deeds?

Question 525: Does Eemaan (Faith) increase with acts of obedience and decrease with acts of disobedience? Please support your answer with evidence. What is the ruling on those who deny that?

Answer: It is true that Eemaan increases with acts of obedience and decreases with acts of disobedience. This is confirmed by the unanimous agreement of Ahl al-Sunnah wa al-Jama`ah (adherents to the Sunnah and the Muslim mainstream) including the Companions (may Allaah be pleased with them) and the scholars and the religious figures who followed their path. Allaah, the Exalted, says, And Allaah increases in guidance those who walk aright. Moreover He, the Exalted, says..read more here.

How can Muslims strengthen their Eemaan (Faith)?

Question 524: What are the means of strengthening Muslims Eemaan (Faith)? May Allaah reward you with the best.

Answer: Some of the means through which you can strengthen your Eemaan and deepen your Yaqeen (certainty), are your decisive belief in the six pillars of Eemaan in addition to your deeds which deepen your Eemaan. The pillars of Eemaan are: The belief in Allaah (Glorified and Exalted be He), His angels, His Messengers, His Books, in the Last Day and in the Divine Decree whether good or bad..read more here.